Rotational machining operations, such as milling, boring, reaming and deburring generally utilize a rotating spindle for interfacing with cutting tools having a variety of designs and geometries. In order to securely retain such tools, tool holders are often provided with adapters suitable for receiving a multiplicity of differently sized and/or shaped tool shanks. Tool adapters, for example, can be used to facilitate rapid replacement of differing tool shank geometries or sizes leading to cutting operation efficiencies. However, such configurations generally introduce metal-to-metal contact surfaces capable of generating undesirable wear and vibrations during cutting operations. Vibrations induced during a cutting operation can shorten tool life and/or reduce workpiece surface finish. Transfer of vibrational resonance into a tool holder can also, in certain cases, result in an unsecure coupling between the cutting tool and the tool holder.
Tool holder assemblies, therefore, must be capable of accurately and securely retaining a tool while minimizing detrimental effects of vibration and wear during a machining operation. Various mechanisms and configurations have been developed for securing cutting tools into tool holder assemblies, but such configurations present deficiencies in minimization of vibration, simplification of design and scalability of design. Tool holder design continues to evolve in response to the changing demands of rotational cutting, milling and boring applications, thereby calling for the development of new assemblies and associated methods of assembling tool holders.